I. Field
The present disclosure relates generally to communication, and more specifically to techniques for deriving a channel estimate for a communication channel.
II. Background
In a communication system, a transmitter typically processes (e.g., encodes, interleaves, and symbol maps) traffic data to generate data symbols, which are modulation symbols for data. For a coherent system, the transmitter multiplexes pilot symbols with the data symbols, processes the multiplexed data and pilot symbols to generate a radio frequency (RF) signal, and transmits the RF signal via a communication channel. The channel distorts the RF signal with a channel response and further degrades the RF signal with noise and interference.
A receiver receives the transmitted RF signal and processes the received RF signal to obtain samples. For coherent data detection, the receiver estimates the response of the communication channel based on the received pilot and derives a channel estimate. The receiver then performs data detection (e.g., equalization) on the samples with the channel estimate to obtain data symbol estimates, which are estimates of the data symbols sent by the transmitter. The receiver then processes (e.g., demodulates, deinterleaves, and decodes) the data symbol estimates to obtain decoded data.
The quality of the channel estimate may have a large impact on data detection performance and may affect the quality of the symbol estimates as well as the correctness of the decoded data. There is therefore a need in the art for techniques to derive a high quality channel estimate in a communication system.